The concept of traffic conflict was initiated in the Uni ted States in
the 60s and raised a lot of interest in many countries: it was an
opening towards the develop- ment of a new tool for safety evaluation
and the diagnosis of local safety pro- blems. The need for such a tool
was great, because of the many situations where accident data was either
scarce, unsatisfactory or unavailable. Development of Traffic Conflict
Techniques (TCT) started simultaneously in the 70s in several European
count ries and new studies were also undertaken in the Uni ted States,
Canada and Israel. The need for international cooperation was rapidly
feIt, in order to exchange data, compare definitions and check
progresses. An Association for International Cooperation on Traffic
Conflict Techniques (ICTCT) was therefore created, grouping researchers
and safety administrators, with the aim of promoting and organising
exchange of information and common practical work. Three Traffic
Conflict Techniques Workshops were organised, in Oslo (1977), Paris
(1979) and Leidschendam (1982). A small scale international experiment
of calibra- tion of TCTs was also carried out in Rouen, France, in 1979,
and five teams took part in it from France, Germany, Sweden, the United
Kingdom and the United States; results of this first experiment were
used as a basis for the present enterprise. To be acknowledged as a
safety measuring tool, traffic conflict techniques had to be validated
in relation to traditional safety indicators such as injury-accidents.